The experience of loneliness among a large number of teenage subjects is studied. Loneliness is defined as a painful inner craving for intimacy and closeness which, unlike depression, is characterized by hope. Adolescents are highly vulnerable to feelings of loneliness because of the push toward independence essential to their developmental stage. In their comparative survey of loneliness in over three thousand adolescents, the authors found the following statistically significant results: 1. Twelve- to fifteen-year-old boys and girls reported more loneliness than did sixteen- to twenty-year-olds. 2. Irish and Australian subjects (more stable societal rules?) reported less loneliness than their American counterparts. 3. Boys and girls who were in psychiatric hospitals and those in residential therapy for delinquency reported more loneliness than did normals. There was no significant difference between boys and girls of comparable ages.